Microalloying and finishing steel with regard to chemical composition in the ladle

The authors discuss a new technology for adjusting the chemical composition of steel with regard to silicon and carbon and for microalloying the steel with vanadium and titanium on a ladle-type finishing unit (LFTU). The steel was deoxidized and carbonized and after the steel was averaged out by blowing with argon, analyzed and brought to the proper temperature, the following adjusting and microalloying additions were made: ferrotitanium with a 30-42% Ti content; ferrovanadium with a 35-50% V content; ferrosilicons FS45 and FS65 and graphite. The microalloying and correcting additions were added when the temperature of the metal was optimum. In trial heats in which the steel was tapped into a ladle with a basic lining, it was noted that the type of ladle lining has almost no effect on the assimilation of vanadium, titanium, silicon, manganese, aluminum, and niobium added to the LFTU. The comprehensive technology developed for finishing steel in large ladles makes it possible to increase assimilation of elements by 5-10%, reduce ferroalloy consumption by 0.4-4 kg/ton and reduce the amount of metal rejected for incorrect chemical composition.